Diaphanosoma excisum Sars, 1885

Pascual, Jhaydee Ann F., Rizo, Eric Zeus C., Han, Boping, Dumont, Henri J. & Papa, Rey Donne S., 2014, Taxonomy and distribution of four Cladoceran families (Branchiopoda: Cladocera: Moinidae, Bosminidae, Chydoridae and Sididae) in Philippine inland waters, Raffles Bulletin of Zoology 62, pp. 771-794 : 783-784

Diaphanosoma excisum Sars, 1885

Specimen examined. Seven parthenogenic female ( UST ZRC 0105 , 0107 - Lake Palakpakin, Laguna; 0106- Lake Buhi, Camarines Norte; 0108- Fish Pond , Laoagan Inn Resort , Kalinga; 0109- Lake Taal , Batangas, 0110, 0111- Lake Cassily , Cagayan) .

Description. The species is common throughout the inland waters of the country. Almost always co-existing with D. sarsi , it can easily be differentiated from the latter with its strongly-developed dorsal part on its head. This gives its head a well large rectangular appearance. Eye ranges from moderate to large. Its carapace oblong-oval in shape, with ventral parts forming a narrow free flap with feathered margins. Its ventral margins have large sharp denticles. It is fairly common in the tropics and subtropics, It can survive different environments from highly turbid to slightly saline waters ( Chatterji et al., 1995) ( Figs. 25, 26 ).

Distribution. Ilocos Norte: Lake Paoay; Cagayan: Lake Nalbuan, Lake Calig, Lake Nagatutuan, Lake Cansiritan, Lake Cassily; Benguet: Ambuklao dam; Kalinga: Fish pond in Laoagan Resort Inn in Tabuk; Pangasinan: Fish pond in Burgos; Tarlac: Lake Tambo; Nueva Ecija: Pantabangan Dam; Zambales: Lake Mapanuepe; National Capital Region (NCR): Pasig River; Marikina River; Laguna: Lake Bunot, Lake Yambo, Lake Mohicap, Lake Palakpakin, Lake Pandin, Lake Sampaloc, Lake Tadlak, Lake Kalibato, Lake Lumot- Mahipon, Laguna De Bay; Batangas: Lake Taal; Camarines Sur: Lake Bato, Lake Baao, Lake Buhi; Oriental Mindoro: Lake Naujan; Leyte: Lake Bito; Bohol: Malinao Dam; Agusan del Norte: Lake Mainit; Lanao del Norte: Agus IV Dam, Tubud-Mayahay River; Bukidnon: Lake Pulangi, Lake Pinamaloy; South Cotabato: Lake Siloton ( Fig. 23 )

Remarks. D. excisum is also distributed in tropical and subtropical Australia, India, Eastern China, Nepal and possibly Northern Africa. One of the more adaptable sidids, it can survive in acidic, turbid and even slightly brackish waters. It is common to water bodies with aquaculture and co-existing with other limnetic cladocerans. It can be easily differentiated from D. sarsi with the strong dorsal portion of its head and more massive antennae.

Figures

Fig. 26. Scanning electron micrographs of Diaphanosoma excisum. A, distal part of first segment of upper 2-segmented antennal branch; B, postero-ventral valve margin; C, ventral valve inflexion; D, terminal claws of post abdomen.

Fig. 23. Distribution of family Sididae based on recently collected samples (2013) and stored samples in the UST ZRC.